When I reboot, the wallpaper always defaults to a particular wallpaper, rather than the one I had selected before reboot. I can of course quickly change this every time, but I'd guess this behavior is not entirely intended? At least when I started using DSL, I can't remember it doing this. I can't remember when it started behaving this way, and I don't think I've messed with the setup - other than to change wallpaper every now and then..